The Evening News reported last week how work was expected to be finished on Haymarket Terrace today - two months behind schedule.
But workers and shoppers heading into the city this morning found diversions so a new £2.5m sewer could be installed still in place.
A Scottish Water spokeswoman said: “Due to unforeseen traffic management issues at Haymarket Terrace, we were unable to reopen the road to two-way traffic today as planned.”
Gas firm SGN has announced it plans to dig up the other side of the street to replace old gas mains with new plastic piping.
“We are now working with SGN to re-open to the road as soon as possible. We apologise for the disruption caused and appreciate your continued patience and understanding,” added the Scottish Water spokeswoman.
The gas works will run between Rosebery Crescent and Magdala Crescent with traffic flowing in both directions but reduced to two lanes with the Coates Gardens junction closed.
Work will start on August 17 and is expected to finish by early October - before a second phase later in the year in Roseburn Terrace.
Drop-in sessions are being held at Apex Haymarket Hotel on Tuesday August 14 between 4.30pm and 8.00pm in a bid to keep businesses informed.
Work on the new sewer began last September and was expected to take nine months and was devised to reduce the risk of flooding to businesses on Haymarket Terrace.
It forms part of a £29.5m water and wastewater infrastructure renewal programme across the Capital, with city council backing.
Scottish Water’s alliance partner Amey Black and Veatch (aBV) were brought in to update the original egg-shaped brick Victorian sewer.
The project comprises of four main phases to install a new 1.2m diameter storm storage sewer pipe, starting on Haymarket Terrace at the junction with Magdala Crescent and moving east towards Haymarket Station.
Join our Facebook group Our Edinburgh to share images and news from and around the Capital